The Diagnostic Laboratory Resource provides the following support services for The Jackson Laboratory (TJL) Cancer Center, quality assurance of the health status of the mice, diagnostic evaluation of specific animals or lesions for Cancer Center members, and consultation services in clinical and anatomic pathology. Quality assurance of the health status of mice from the Research Animal Facility (RAF) is achieved through routine health monitoring of mice from each room in the RAF on a quarterly basis. These animals are sent to the Diagnostic Laboratory for gross necropsy, microbiologic culture, PCR, parasitologic and serologic evaluation. Health status monitoring also includes routine sampling of supplies and the environment for evidence of pathogenic organisms. Diagnostic testing of specific animals or lesions is accomplished primarily through the "sick mouse" program. Under this program mice (belonging to TJL Cancer Center investigators) with questionable health or lesions of unknown origin are submitted to the Diagnostic Laboratory for evaluation including culture, PCR, and histopathology. The primary goal of the evaluation is to determine whether the lesions resulted from experimental treatment, genetic mutations, or infectious diseases. Consultation services in clinical and anatomic pathology are provided to the Cancer Center members to assist them in the characterization and documentation of aberrant phenotypes generated as part of the investigators research program. This includes examination of tissues by light microscopy and measurement of clinical chemistry and hematology values. The clinical chemistry is performed on a Beckman Synchron CX5 Delta analyzer. Hematologic values are determined with a Bayer Advia 120 analyzer. The Diagnostic Laboratory Resource is under the direction of James R. Fahey, Ph.D., M.S., D.V.M. who has over 25 years experience in microbiologic sciences, and includes consulting pathologists, Drs. Sunberg and Bronson. In addition, the Diagnostic Laboratory has seven technicians with extensive experience in their respective areas of clinical pathology, microbiology necropsy services, and special tissue preparation and staining techniques.